Thread (11 messages) 11 messages, 3 authors, 2019-08-23

Re: [PATCH v1 1/5] pinctrl: mediatek: Check gpio pin number and use binary search in mtk_hw_pin_field_lookup()

From: Sean Wang <sean.wang@kernel.org>
Date: 2019-08-13 22:54:42
Also in: linux-mediatek, lkml

On Tue, Aug 13, 2019 at 1:53 AM Light Hsieh [off-list ref] wrote:
From: Light Hsieh <redacted>

1. Check if gpio pin number is in valid range to prevent from get invalid
   pointer 'desc' in the following code:
        desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

2. Use binary search in mtk_hw_pin_field_lookup()
   Modify mtk_hw_pin_field_lookup() to use binary search for accelerating
   search.

Change-Id: I22b4644ec216b90dd9dd5e223cc41d43761701b0
remove all of Change-Id in all the patches in the series
quoted hunk ↗ jump to hunk
---
 drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c | 24 +++++++++++++++++++-----
 drivers/pinctrl/mediatek/pinctrl-paris.c         | 19 +++++++++++++++++++
 2 files changed, 38 insertions(+), 5 deletions(-)
diff --git a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
index 20e1c89..4687f63 100644
--- a/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
+++ b/drivers/pinctrl/mediatek/pinctrl-mtk-common-v2.c
@@ -68,7 +68,7 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
 {
        const struct mtk_pin_field_calc *c, *e;
        const struct mtk_pin_reg_calc *rc;
-       u32 bits;
+       u32 bits, start = 0, end, found = 0, check;
variable found should be bool type, and the declaration should be
listed in reverse Xmas tree order
quoted hunk ↗ jump to hunk
        if (hw->soc->reg_cal && hw->soc->reg_cal[field].range) {
                rc = &hw->soc->reg_cal[field];
@@ -79,21 +79,32 @@ static int mtk_hw_pin_field_lookup(struct mtk_pinctrl *hw,
                return -ENOTSUPP;
        }

+       end = rc->nranges - 1;
        c = rc->range;
        e = c + rc->nranges;

-       while (c < e) {
-               if (desc->number >= c->s_pin && desc->number <= c->e_pin)
+       while (start <= end) {
+               check = (start + end) >> 1;
+               if (desc->number >= rc->range[check].s_pin
+                && desc->number <= rc->range[check].e_pin) {
+                       found = 1;
found = true;
quoted hunk ↗ jump to hunk
                        break;
-               c++;
+               } else if (start == end)
+                       break;
+               else if (desc->number < rc->range[check].s_pin)
+                       end = check - 1;
+               else
+                       start = check + 1;
        }

-       if (c >= e) {
+       if (!found) {
                dev_dbg(hw->dev, "Not support field %d for pin = %d (%s)\n",
                        field, desc->number, desc->name);
                return -ENOTSUPP;
        }

+       c = rc->range + check;
+
        if (c->i_base > hw->nbase - 1) {
                dev_err(hw->dev,
                        "Invalid base for field %d for pin = %d (%s)\n",
@@ -182,6 +193,9 @@ int mtk_hw_set_value(struct mtk_pinctrl *hw, const struct mtk_pin_desc *desc,
        if (err)
                return err;

+       if (value < 0 || value > pf.mask)
+               return -EINVAL;
+
        if (!pf.next)
                mtk_rmw(hw, pf.index, pf.offset, pf.mask << pf.bitpos,
                        (value & pf.mask) << pf.bitpos);
diff --git a/drivers/pinctrl/mediatek/pinctrl-paris.c b/drivers/pinctrl/mediatek/pinctrl-paris.c
index 923264d..28b4951 100644
--- a/drivers/pinctrl/mediatek/pinctrl-paris.c
+++ b/drivers/pinctrl/mediatek/pinctrl-paris.c
@@ -693,6 +693,9 @@ static int mtk_gpio_get_direction(struct gpio_chip *chip, unsigned int gpio)
        const struct mtk_pin_desc *desc;
        int value, err;

+       if (gpio > hw->soc->npins)
+               return -EINVAL;
+
        desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

        err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DIR, &value);
@@ -708,6 +711,9 @@ static int mtk_gpio_get(struct gpio_chip *chip, unsigned int gpio)
        const struct mtk_pin_desc *desc;
        int value, err;

+       if (gpio > hw->soc->npins)
+               return -EINVAL;
+
        desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

        err = mtk_hw_get_value(hw, desc, PINCTRL_PIN_REG_DI, &value);
@@ -722,6 +728,9 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)
        struct mtk_pinctrl *hw = gpiochip_get_data(chip);
        const struct mtk_pin_desc *desc;

+       if (gpio > hw->soc->npins)
+               return;
+
        desc = (const struct mtk_pin_desc *)&hw->soc->pins[gpio];

        mtk_hw_set_value(hw, desc, PINCTRL_PIN_REG_DO, !!value);
@@ -729,12 +738,22 @@ static void mtk_gpio_set(struct gpio_chip *chip, unsigned int gpio, int value)

 static int mtk_gpio_direction_input(struct gpio_chip *chip, unsigned int gpio)
 {
+       struct mtk_pinctrl *hw = gpiochip_get_data(chip);
+
+       if (gpio > hw->soc->npins)
+               return -EINVAL;
+
        return pinctrl_gpio_direction_input(chip->base + gpio);
 }

 static int mtk_gpio_direction_output(struct gpio_chip *chip, unsigned int gpio,
                                     int value)
 {
+       struct mtk_pinctrl *hw = gpiochip_get_data(chip);
+
+       if (gpio > hw->soc->npins)
+               return -EINVAL;
+
        mtk_gpio_set(chip, gpio, value);

        return pinctrl_gpio_direction_output(chip->base + gpio);
--
1.8.1.1.dirty
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